Electric lamp



Jun 3, 1930. H. A. DOUGLAS ELECTRIC LAMP I Filed Jime 14, 1929 iii/(5 07JozgZaa Patented June 3, 1930 PATENT QFFICE HARRY A. DOUGLAS, 01IBR-O'NSON, MICHIGAN ELECTRIC LAMP Application filed June 14,

. My invention relates to electric lamps employing shields for partiallyobstructing light emanating therefrom.

. In accordance with my invention, the shield is made adjustable and isin controlling relation to a switch that governs the circuit of theassociated lamp so that'when the shield is in one position the lampcircuit is closed and when in an alternative position the lamp circuitis opened. Inthe preferred embodiment of the invention, such adjustableshield constitutes the shutter for an opening in a cowl that surroundsthe lamp and which cowl serves further to obstruct light emanating fromthe lamp, such shutter serving to close the switch when the shutter isopened and to open theswitch when the shutter is moved in a closingdirection sufficiently to completely close the opening, though theinvention is not to be thus restricted.

The invention will be more fully explained in connection with theaccompanying drawing in which Fig. 1 is a front view illustrating thepreferred embodiment of my invention adapted to furnish illumination forthe instrument board of an automotive vehicle, the shutter being shownin an open position; Fig. 2 is a sectional view on line 2-2 of Fig. 1;Fig. 3 is a sectional view on line 3+3 of Fig. 2; Fig. 4 is a sectionalview on line H of Fig. 3 Fig. 5 is a sectional View on line 55 of Fig.3; Fig. 6 is a view similar to Fig. i but showing the shutter in aclosed position; and Fig. 7 is a sectional view on line 7-7 of Fig. 5,parts being broken away.

The cowl 1, preferably metallic, is of any suitable shape. This cowl iselectrically grounded. As illustrated, it is oblong and has flat top andbottom sides which are joined by semi-cylindrical end portions 2 and 3and a rounded front portion 1. A metallic shutter is provided to openand close the opening 5 in the'cowl, said shutter having transverse l.extendin ears 5 5 which are 'ournaled y a: a

upon the inner and reduced ends of metallic pins 5 of the cowl. Theshutter may be provided with a thumb and finger piece 5 whereby it maybe opened and closed. The light emitting opening 5 extends lengthwise ofthe cowl but terminates, at each end, short 1929. Serial No. 370,871.

of the semi-cylindrical portions 2 and 3 since it is found that thisopening need not be sector shaped when the structure is used upon thedash board of an automobile. The metallic lampsocket 6 is provided withtongues 7 at its front end which are clinched against the front side ofan oblong plate 8 of insulation which is surrounded by and snuglyreceived within tl e rear end of the cowl, the plate 8 having sometongues 9 which enter spaces between the tongues 7, these tongues 7clamping the plate against the body of the socket 6. By thisarrangement, the socket is firmly held from movement in any directionwith respect to the insulating plate which insulates the socket from thecowl.

inwardly projecting attaching formations, preferably tongues, 10 and 11are integrally formed with the cowl near the ends and at the top sidethereof. Inwardly projecting tongues 12 and13 are integrally formed withthe cowl near the ends and at the bottom side thereof. The tongues 10and 12 are in lapping relation as are the tongues 11 and 13. Registeringholes 14 are formed in the tongues 10 and 12 and registering holes 15are formed in the tongues 11 and 13. The holes 14: are in register withthe hole 16 formed in the insulating plate 8 and the holes 15 are inregister with another hole 17 formed in said plate; The shanks 18 ofassembling bolts are passed through the holes that are in register andthrough holes in a mounting or instrument board 19. The heads of thebolts are within the cowl and engage the tongues 12 and 13. Nuts 20 arescrewed upon the threaded shanks of'the bolts, said mounting board, theplate 8 and the tongues through which the bolt shanks pass being clampedby the nuts between the bolt heads and the nuts whereby the cowl and thelamp socket are secured in fixed position upon the mounting board. Saidsocket projects through an opening 21 which is formed in the mountingboard.

The front end of the socket is provided with bayonet slots or channels22 which are adapted to receive the metallic bayonet pins or projections23 extending radially from the base 2 1 of an incandescent lamp bulb 25,this bulb being entirely within the interior of the cowl when its baseis fully assembled with said socket. I have illustrated a single polelamp in which one terminal of the filament is suitably connected with ametallic sheath provided upon the base of the lamp bulb to haveelectrical contacts with the metallic socket 6 and to be further placedin electrical connection with this socket through the intermediation ofthe metallic pins 23 that are electrically connected with said sheath.The other terminal of the filament is connected with the contact button26 that is provided upon and insulated from the rear end of the base 2&.The lamp socket 6 encloses a coiled spring 2'? and two insulatingwashers 28 and 29 between which the spring is interposed, the rearwasher 29 being seated upon the inturned rear end of socket 6 and theforward washer 28 carrying a contact 30 which is pressed, by the spring27, into electrical engagement with the contact 26. The wire 31 extendsfrom one pole of a battery, whose other pole is grounded, and terminatesin the contact 30.

The socket 6 has an elongated late-rally ex tending continuation 32 thatis integrally formed therewith and which terminates in a cam portion 33which is located in the region of the ear 5 upon the shutter. A cam 34is mechanically connected with the ear 5 The cam 34 moves with and is sorelated to the shutter 5 that when the shutter is opened, such cam 34'will be free from the cam 33 to permit contact 32 to press against themetallic cowl 1 to complete the electrical connection between thegrounded pole of the battery and the metallic socket 6, (Figs. 3 and 1')this connection being extended through the metallic bayonet pins 23 andthe sheath upon the lamp base to one terminal of the filament, the otherterminal of the filament being connected with the ungrounded pole of thebattery as previously described. Thus the lamp circuit is closed whenthe shutter is opened. When the shutter is closed, the aforesaid cam 34engages the cam 33 to separate contact 32 from the cowl (Figs. 5 and 6)to open the lamp circuit. By this arrangement, the provision of aseparate and individually operated switch upon the instrument board forcontrolling the lamp circuit is not required, the equipment being thuscheapened and space being economized.

A finishing washer 35 of dish form may receive the rear of the cowl.This finishing washer has openings 36 through which the bolt shanks arepassed. The margins of the openings 36 initially enter the screw threadsof the bolt shanks, slots 37 radiating from said openings 36 tofacilitate the threaded engagement of the bolts with such openingmargins. The bolts have annular recesses 38 adjacent the bolt heads andclear of the threads in which recesses the margins of the openings 36are ultimately received when the bolts are sufficiently turned wherebythe bolts may thereafter be turned without disturbing the Washers whichare thereby prevented from interfering with the mounting of thestructure which is effected by the bolts. When the margins of theopenings 36 are received in the recesses 38, such margins are notreadily restored into engagement with the threads of the bolts, whichthreads thus serve to maintain the washers in place about the boltshankswhile the devices are in shipment and in stock and before they areassembled with mounting boards, a feature of much advantage, it notbeing necessary to rely upon the nuts for this purpose. When the devicesare to be mounted in place, it is merely necessary to project thethreaded bolt shanks through the corresponding holes in the mountingboards and thereafter apply the clamping nuts.

Having thus described my invention, I claim:

1. The combination with an electric incandescent lamp having a metallicsheath upon its base and a filament having one terminal in electricalconnection with this sheath; of a metallic socket receiving the base ofthe lamp and with which said sheath is engaged; an adjustable shutterfor obstructing light emanating from the lamp; and a switch for openingand closing the circuit of the lamp and operable by the shutter, theaforesaid metallic socket having an extension constitutin one of thecontacts of the switch, the switch and shutter being so related that theswitch is opened when the shutter is closed and the switch is closedwhen the shutter is open.

2. The structure of claim 1 wherein the lamp is provided with a metalliccowl that is in the lamp circuit and which cowl constitutes a switchcontact complemental to the contact that is formed of the socketextension.

In witness whereof, I hereunto subscribe my name.

HARRY A. DOUGLAS.

